If you're too lazy to read through 82 pages worth of a thread to find answers to your $40,000+ truck:
1. There is NO fix as of yet for the gen 3 coyote (2018+) 5.0L rattle on deceleration rattle. The TSB did not solve the issue. No one, not even Ford can not determine what the cause is. Ford will determine it is "normal" while all owners will argue that it is not a "normal" characteristic of a competently engineered engine.
2. There has not been a single case on this thread of a catastrophic engine failure due to this "rattle on deceleration."
3. Cam Phasers, tensioners, and chains have been replaced according to posts on this this thread with no avail.
4. Some have been successful in a "buy back" or "lemon law" cases.
5. Not all generation 3 coyote 5 Liter engines have this issue, however according to the sample size of this thread a majority have the issue.
6. By reporting the issue with Ford (see my previous posts to see how and what phone #'s you need to call) you can document your problem (the earlier the better for you) and will receive a better buy back value or lemon law value for your truck if the situation arises.
7. Personally, after my experience with the local dealership and the Ford CRC (Customer Relations Center)... My truck is worse off physically after all is said and done. I have a 5 PAGE WORD DOCUMENT of how the local dealership has messed up my truck. Here's a link to that thread: Nightmare at the Dealership.
8. I have personally received a "free" extended warranty from Ford CRC (5 year/ 75,000 mile) for my troubles, even though literally nothing has been resolved.
9. According to speculation, it is most likely an engine oil deficiency issue (especially when you consider their past V8 engines). I have done an experiment comparing the factory recommended oil (Motorcraft 5w-20 synthetic blend) vs. full synthetic blend Pennzoil products. Please stay tuned to YouTube channel: StudioTron… I will post a video with the results. Hopefully this will help you choose the right oil for this engine. I plan to do an oil analysis with each oil change (current oil is Motorcaft 5w-20 with motorcraft oil filter), my next oil change will be Pennziol Ultra Platinum 5w-20 with Wix XP oil filter. I've already done the oil flow testing and the results are surprising. I'll post the results in the next week or two, I just need to clean up the final draft.